Skin cancer is emerging as the fastest growing type of cancer being reported, especially for the population at or near typical retirement ages. There are three common types of skin cancer: basal cell carcinoma, squamous cell carcinoma, and melanoma. Of the three, melanoma is the most dangerous because it is the variant most likely to metastasize and spread to the rest of the body.
Early detection of skin cancer is critical to preventing such spreading. Presently, the most reliable test for skin cancer is a skin biopsy. Unfortunately, however, diagnosing skin cancer from an excised sample of skin can be disadvantageous. For example, because the excised sample is small and the dissection of the sample is random, a diagnosis based on biopsy may be inaccurate. Moreover, if a cancer diagnosis is made, the patient may be required to return for further biopsies until the extent of the cancer is determined, resulting in multiple biopsy procedures and, potentially, the unnecessary removal of healthy skin. In addition, complications can arise as a result of biopsy, such as infection, hemorrhage, and the spreading of cancer cells.
Furthermore, no imaging technology currently exists that can be used to accurately identify the extent of cancerous lesions for purposes of surgical resection. Although optical coherence tomography (OCT) and optical coherence microscopy (OCM) have emerged as noninvasive technologies that show promise for replacing skin cancer diagnosis via biopsy, neither has been able to provide histological level resolution throughout the region that can contain early developing anomalous cells. OCT technology has evolved to provide nearly constant 15-20 micron (μm) resolution to depths of approximately 1 millimeter (mm) in scattering media like skin, but the histological examination of a biopsy provides information typically based on the structure of 1-5 μm features. OCM can provide 1-5 μm resolution, but only over a few tens of microns of depth, not the hundreds of microns that are needed. Therefore, neither OCT nor OCM, in their current forms, have removed the need for biopsy.